NTIA to referee wideband interference debate

MANHASSET, N.Y.  The Multiband-OFDM Alliance this week agreed to join Motorola in independent tests being performed by ITS Labs (Boulder, Colo.) to evaluate the interference characteristics of their respective ultrawideband proposals, EETimes has learned. The tests are intended to settle the raging debate between the MBOA and Motorola over whether or not the MBOA proposal can meet IEEE 802.15.3a requirements  while remaining true to FCC requirements.

The debate has reinforced the deadlock between the proposals as they each vie to become the short-range, high-speed physical layer of choice for the IEEE 802.15.3a task group. Motorola claims MBOA cannot meet both IEEE and FCC requirements because it is a frequency-hopping scheme, while the MBOA camp has consistently maintained that it meets the spirit of the FCC's Report and Order issued in 2002.

Martin Rofheart, director of UWB operations at Motorola, said the tests will include a total of five UWB implementations, mostly comprising variations of each proposal's waveforms. "The ITS work order calls for a nine-month timeline," he noted.

The MBOA's decision to join the tests, which were initiated and sponsored and financed by Motorola, came during a joint meeting in Washington D.C. this week between representatives from the FCC, NTIA [National Telecommunications and Information Infrastructure] and MBOA, at which the MBOA presented their proposal.

"My objective is to allow development to go forward but protect the incumbents," said Edmond Thomas, chief engineer at the FCC. According to Thomas, the candle under which the proposals will be compared is "does it create more interference than existing standards  strike one. If so, is it [the interference] significant and does it cause harm to any of the incumbents. That's where some analysis will have to be done." Thomas said the technical details of each will be examined closely, "along with the technical standards of the incumbents [GPS, cellular, satellite and military radios]."

While Motorola has maintained that the MBOA proposal will violate the FCC R&O with respect to frequency hopping, according to Thomas, "The religion isn't whether it hops or not, it's whether or not it interferes. If the NTIA and the FCC agrees that this does not cause any problems, we haven't violated our religion, and there's only one commonsense conclusion to draw. The Holy Grail is to make sure that whatever's deployed in UWB does not cause harm."

While the MBOA proactively go along with the tests, they're a repeat of what the MBOA has already proven, said Roberto Aiello, founder and president of Staccato Communications (San Diego, Calif.), a leading MBOA member. "We've done C-band receiver tests and presented those to the IEEE in January [at the 802.15.3a task group meeting]," he said. "Those showed that we didn't interfere more than impulse radios already allowed by the FCC's rules. Motorola didn't comment on those results."

Aiello believes the tests shouldn't take longer than four weeks, or up to two months at the outside. "Our goal is to come up with a result as quickly as possible," he said.